Influenza epidemics occur every year globally, including in Cambodia. There are two types of seasonal influenza that cause significant human morbidity and mortality: influenza A [A (H1N1) pdm09 and A (H3N2)] and influenza B (B/Yamagata and B/Victoria). The prevalence of influenza infection in Cambodia was 38.4% during 2012 – 2015. We aimed to determine the prevalence of influenza virus infection from 2013 - 2017 and to assess the potential risk factors for human infection with influenza in the four villages of Kampong Cham and Tbong Khmum Provinces.
We analyzed data from 3,756 participants aged 06 years old and above who enrolled from 2013 to 2017 in a study of acute febrile disease among village cohorts in Kampong Cham and Tbong Khmum provinces, Cambodia. We analyzed the data using Stata V16. Descriptive analysis was used to describe the prevalence and demographic characteristics of influenza infection. Multivariate logistic analysis was performed to determine the main risk factors associated with influenza infection.
Among 3,756 enrollees, males accounted for 48.4%. Of the total samples, 1,040 (27.7%) were confirmed to be influenza positive. Most influenza cases were predominantly influenza A viruses (53.6%) and influenza B (46.2%). The influenza infection peak increased in the rainy season. In multivariate logistic analysis, the risk factors associated with influenza infection were aged 6 – 12 years old (AOR = 1.5, 95% CI: 1.12 – 2.02) and 13 – 19 years old (AOR = 1.94, 95% CI: 1.30 – 2.90), primary education of grade 1-6 years (AOR = 1.53, 95% CI: 1.16 – 2.00), cough in the past 2 days (AOR = 2.96, 95% CI: 2.34 – 3.75), runny nose in the past 2 days (AOR = 1.87, 95% CI: 1.55 – 2.26) and chills in the past one day (AOR = 2.03, 95% CI: 1.71 – 2.41)
The highest prevalence of seasonal influenza infection, especially types A and B, mainly emerged in the rainy season from May to October of the years. Age, primary education, seasonal variation, cough, runny nose and chills were the key predictors of influenza infection.